| Etan Cohen | 7ef855e | 2014-08-20 10:11:11 -0700 | [diff] [blame] | 1 | /* AVR-GCC does not have real double datatype. Instead its double |
| 2 | * is equal to float, i.e. 32 bit value. If you need to communicate |
| 3 | * with other systems that use double in their .proto files, you |
| 4 | * need to do some conversion. |
| 5 | * |
| 6 | * These functions use bitwise operations to mangle floats into doubles |
| 7 | * and then store them in uint64_t datatype. |
| 8 | */ |
| 9 | |
| 10 | #ifndef DOUBLE_CONVERSION |
| 11 | #define DOUBLE_CONVERSION |
| 12 | |
| 13 | #include <stdint.h> |
| 14 | |
| 15 | /* Convert native 4-byte float into a 8-byte double. */ |
| 16 | extern uint64_t float_to_double(float value); |
| 17 | |
| 18 | /* Convert 8-byte double into native 4-byte float. |
| 19 | * Values are rounded to nearest, 0.5 away from zero. |
| 20 | * Overflowing values are converted to Inf or -Inf. |
| 21 | */ |
| 22 | extern float double_to_float(uint64_t value); |
| 23 | |
| 24 | |
| 25 | #endif |
| 26 | |